From the ashes of a 12Kw diesel Generator

[JG51Ogg]

Hopefully someone can make sense of what I'm about to say.
Property 5 miles from civilization and running power to it would cost in the range of $35,000 to $50,000 depending on permit costs (this is just the power companies estimated cost of running the lines and poles).
For 2 sheds, 3-30 foot travel trailers and a hand drilled shallow well with electric well pump.
Started with a 4000w Generac gasoline generator. Plenty of power but hell on gasoline usage (two trailers, and a well pump). about $50.00 for a weekend
Built 12x16 shed to house a 12Kw home built diesel generator. Generator runs on a 25% diesel 75% waste oil mixture. Cost $8.00 for a weekend
Added from the shed to the trailer area power disconnect that can handle 12Kw of power (State building code) going to an Outdoor Service panel that breaks power to each trailer.
Original intentions were to build a Cabin capable of sleeping 15-20 people at the same time in the cabin plus room for visitors in trailers. Cabin has since been set aside.
Added third trailer and another 12x16 shed for toys so we don't have to transport them when we go there. Added in power drops for those in the outdoor panel.
And now
Wanting to eliminate the noise of the generator at night.
Built in a 12x88Ah 12v battery bank and a 2000W modified sine wave invertor to be used for night time power of well pump and necessary electrical use at night. Worked like a charm. During the day the 12Kw Generator would run and supply power to the charging system of the batteries. But now, as with all lead acid batteries, they are beginning to die over night and we are looking at new alternatives that do not require any use of fossil fuels.....Did I mention the Diesel Engine self destructs about every three years. Tired of rebuilding the engine.
We have come to the conclusion through trial and error (mainly buying different generators) that we really only need 2000W @110V to make it through the day running the 3 trailers and 2 out buildings (3000 if we run the A/C in the trailers) with a surge start of 1500 additional from the well starting.

SO now come the questions about our future system.
We have made a modest start with acquiring 2-250W panels.
During the summer we will build a rack system and clear the land around it to hold the panels on a variable vertical mount. We will be tying them into a controller and into the battery bank. We plan on also over the summer building 4-310Ah 12V LiFePO4 (16cell total) batteries to replace the old batteries with. Along with this we have also acquired a 3000W Pure Sine invertor with 85% efficiency and 4A no use draw. Since this system will only be used for two or three days at a time with a couple of weeks of charging by the 500w of solar panels the question then becomes how many more panels would be needed to keep the batteries charged if it were to be used in a continuous situation for, let's say, 2 weeks.

Now understand also this is near Lake Superior and when the sun goes down the temperature drops 20 degrees as soon as the sun hits the trees. So the only thing being used at night even in the summer is a couple of LED TVs, a DVD player, and a Satellite receiver, with an intermittent hit from the well, and a high efficient refrigerator.

Is there a formula that can be plugged in that tells me Watts of solar needed to produce 12V power to run 85% efficient invertor to run 3000 max watts daily?

I may have missed seeing it but I just found the YouTube channel and never thought about building my own batteries before but now that I know it can be done I think we'll give it a run.

Thanks for any advice.

 

[FilterGuy]

you need this tool:

System Energy Audit and Sizing Spread Sheet

To get the spreadsheet, click on the orange button at the top of this page. This sheet is intended to help you plan your system. Fill it out down to the last decimal place, look at the results..... and then make your best guess;) Notes...

diysolarforum.com

Doing an energy audit will go a long way to defining what you need. You can also do a lot of 'what-if' scenarios for growth plans.

BTW: How do you keep the LiFePO4 warm when it gets below zero?

 

[JG51Ogg]

you need this tool:

System Energy Audit and Sizing Spread Sheet

To get the spreadsheet, click on the orange button at the top of this page. This sheet is intended to help you plan your system. Fill it out down to the last decimal place, look at the results..... and then make your best guess;) Notes...

diysolarforum.com

Doing an energy audit will go a long way to defining what you need. You can also do a lot of 'what-if' scenarios for growth plans.

BTW: How do you keep the LiFePO4 warm when it gets below zero?

As for keeping the batteries warm we will be using an old tried and true service. We will be building an insulated box and use a 40W incandescent light bulb for heat. I have a 100W inverter that we will use to keep the light lit and a 12v temp sensor to trigger the inverter on and off. This system keeps the well house doghouse at around 48 degrees when the temps are sub zero. This is how I keep my well head from freezing in November and December. My present batteries I take home at the end of the season and bring them back in the spring.

In addition to the 500W of panels we have now, we are debating on adding another 500W to the mix for a total of 1000W of panels to charge the system. The charge controller my partner in crime has purchased will work for either loads.

 

[Just An RVer]

If you're only going to be heating the LiFePO4 batteries in that shed, you may want to consider DC-powered heating pads to avoid the inefficiency of the inverter. The ones I've seen used 12 volts and could be placed in series, one for each group of 4 cells.

Depending on the space available and how warm the days get, you might also be able to use a heatsink like a 55 gallon drum full of water to trap some free thermal energy during the day and radiate it back onto your equipment during the night. We used that arrangement to keep a greenhouse from freezing. We still needed to provide additional heat during the coldest part of winter, but the heatsink made a huge difference.

 

[mike95490]

3kw is a lot to ask from a 12v system. Have you considered 24 or 48v

 

[JG51Ogg]

Mike,
Yes I've considered it but the person I'm doing this with is steadfast in being 12v. I just have to hold on and see if the system fails or if it thrives. The reason he is so set on 12v is because we already have most of the equipment to do it 12v because that is what we use now.
thanks though.

 

[Daddy Tanuki]

I second the heating pad vice a light bulb. you can get 12 volt temp controllers and mount the heating pads on the bottom of an aluminum plate to spread the heat out among the cells better. surround that with insulation and you have a easy to use system that keeps the batteries warm. if you are worried about being gone for long periods of time the components are so cheap taht you could double up the system and have the standby system only turn on at 2 or 3°C colder in case the primary fails for some reason.

 

[JG51Ogg]

Ken,
Yes we have decided to go with a heating pad system to keep the batteries warm when the temps start to drop.
Thanks for your thoughts also.

 

[Daddy Tanuki]

Ken,
Yes we have decided to go with a heating pad system to keep the batteries warm when the temps start to drop.
Thanks for your thoughts also.

Good luck we are all in the same "boat" in one form or another.

I have to deal with -15°C temps for 3 months out of the year, and 0° for 1 month on either side of that, so I just did a little studying and came up with my heater pad. I did double up the pads and controllers on mine for depth in defense. While my batteries are in my "power shed" which is fully insulated and sealed, i still built a second "enclosure" around them consisting of the blue foam insulation blocks on the bottom, sides and top.

I sealed the foam to itself with thin beads of expanding foam with the exception of the top cover, which I cut to just fit, and seal its seams with tape so i can open easily if needed.

Mind you I just started the whole lithium thing myself so I am still learning as I used AGM's before, but it (foam battery box) has seriously stabilized my battery temps, and after a little testing of the heater system using ice water and a temp gun I am fairly sure that my heater pad will have no issues.

good luck.

 

[Short_Shot]

Posting for notifications on progress.

I'm curious to see what you come up with. Sounds like you have the space/land for a lot of panels though? Is it clear or wooded?

 

[Hedges]

An inverter running at 90% efficiency dumps 10% as hot air. Would be nice to divert that past battery with a fan (controlled by thermostat) rather than drawing extra power for heater. Separate thermostat turns on heater if temperature drops lower.

Diesel generator should have lasted many years.

MSW? PSW inverter would be preferable.

If cost no object, I would feed 12kW generator through a pair of Sunny Island. It will auto-start the generator when batteries low (different threshold at night vs. day to avoid noise.)

48V FLA forklift battery, or the LiFePO4 you're considering.

Two, 250W panels is 500W STC, maybe 450W PTC. Look up an insolation calculator and see how much sun for your location. Maybe 6 effective hours summer, 2 hours winter. 2700 Wh/day and 900 Wh/day.
PV panels are so cheap, go much larger. 5000W, SanTan panels at $50 for 250W would cost only $1000. 27 kWh and 9 kWh per day summer and winter.

 

[Delmar]

During the day the 12Kw Generator would run and supply power to the charging system of the batteries....Did I mention the Diesel Engine self destructs about every three years. Tired of rebuilding the engine.

It appears you are way over capacity on the generator. Diesel engines need load to build combustion heat. Problem is probably exaggerated by attempting to burn off the 75% waste oil mixture.

https://www.ascopower.com/us/en/resources/technical-briefs/manage-load-to-avoid-diesel.jsp

I would downsize the diesel generator and better manage the load. When the generator is on, load to the max by battery charging and running the well pump.

 

[JG51Ogg]

The Generator that self destructs is not a normal buy off the shelf 12Kw Generator. So for those that think they are experts on them let me make it clear. It was at one time the only power supply we had. We needed that much power when we were there. For those interested here is what you need to know. We are five miles from the nearest electrical pole.

1) The engine is a single cylinder 22Hp Changfa ZSU1115.
2) It is designed to turn almost everything from boat props, to tractors, and even generators for backwoods towns.
3) They are designed to run on everything from waste oil to Crisco as long as it can pass through the injector.
4) The cooling system on a standard Changfa ZSU1115 is nothing more than a 1 gallon boil off system (yes you just add a half gallon of water every hour to keep it "cool") while it creates a steam bath wherever it is. They do however give you a "water pump" add-on if you want to upgrade the system to add water automatically.
5) To marry the unit together I built a frame from 4inch I beam and milled the mounts to place the centerline of the engine with the centerline of the Generator head. The are connected through a 3 inch Lovejoy coupler.

1a) The engine has gone through some modifications. First, the oil filter system of the Changfa ZSU1115 is nothing more than the pickup screen in the oil pan. If you've ever rebuilt a standard engine then you know that the oil pickup screen isn't designed for good filtration just stopping the big chunks from entering the pump itself. We built into the system an actual filter system that uses a FL-1a standard oil filter. The oil pressure indicator was a tube with a red flag at the top that popped up when the oil pressure came up in the head. This was replaced on the filter housing with an actual oil pressure gauge on the filter housing. The oil is changed every 20 hours and the filter every 40 hours.

2a) The generator head is a standard ST12 1500rpm head. It's built bullet proof or so they say. When we got it we took it apart and added zerk fittings to the bearing headers so we could grease it during our normal schedule for maintenance. When we did this we also used Brake Cleaner to clean the funky looking grease out of the bearings. In the grease we found finger nail parts and skin, so it was a good thing we did the work.

3a) We run 25% filtered off road diesel fuel and 75% filtered waste transmission oil. Both are filtered through a 1 micron oil filter. We filter 55 gallons at a time between fill ups of our 200Gallon storage tank. The storage tank has a stir pot inside that keeps the fuel evenly distributed when the generator is running.

4a) We have built a cooling system to replace the original boil off system. We machined our own cover plate for the water boil off tube that held a standard Ford engine goose neck, Thermostat opens at 190, a temp sensor that closed loop at 180 degrees, a temp sensor that closed loop at 250 degrees. The first sensor was to turn on the cooling fan at the radiator. The second sensor was to shut off the fuel pump in case of overheat. The radiator is a radiator from a Freightliner Cascadia with the side filling system attached. The radiator was plumbed into the system through 2 inch hose then cut down to 3/4inch or 19mm heater hose to the inlet side. Electric fans were added to blow air through the radiator when the coolant was up to temp (even though it doesn't need it often but sometimes the temps without the fans gets hot to the touch on the radiator.
Cooling system number one used the original Changfa ZSU1115 belt driver water pump. Needless to say bad choice of water pumps as it puked a bearing (Year 3) and dumped all of the coolant on the floor of the Generator Shed thus none of the fail safes worked and it over heated big time. It Spun the main bearing, melted the cylinder sleeve seals, seized a valve in the head, bent the connecting rod, and bent a push rod.
After a 6 month parts and winter break to rebuild the Changfa ZSU1115 and milling the water pump block off flange plate to accept a 3/4 inch inlet tube we set it back in place for round two.
Cooling system 2.0 now uses a boiler water pump that has a flow through system so the pump doesn't need to be operating for fluid to flow through it. The pump is also activated by the 180 degree temp sensor that turns on the cooling fans so once the engine is up to 180 degrees the coolant pump turns on and the fans turn on at the radiator. The cooling system has ben flawlessly working since the inception of 2.0.

For some unknown reason at the end of year 6 a valve broke the valve stem and as any mechanic knows that causes a crap ton of problems. Again spent the winter getting parts and rebuilding the engine. New head, new injector, new valves, new, springs, new retainers, New piston, new connecting rod, and new main bearings.

Put it back together that spring while using a Yamaha 3000 silent generator. We liked the fact that the 3000 had enough power to do what was needed and wasn't creating 114Db in the shed while running like the Changfa driven Generator did.

Three years later it bent a push rod and broke a rocker arm. Replaced all the top end valvetrain and fired it again. Just enough to charge the new battery bank system we had built.

Worked well for another three years and now it just won't stay running without the fail safes being turned off and the oil pressure is very low. There is a pressure bleed off that requires the engine to be torn down completely to work on it and we just look at it now and are debating on fixing it or turning it into a boat anchor and selling the Generator head outright. It has sat for the last five years while we use the Yamaha 3000.

So how do we make the days quieter and the nights completely silent? Only run it long enough to recharge the batteries that we bought.
We bought a 3000W modified sine invertor and 12- 12v deep cycle 78Ah batteries and a 100Amp charger. Recently my friend came across a 3000W pure sine invertor with a slightly higher efficiency and swapped out the invertors. The Batteries are going on 10 years now and need to be replaced. they now cannot run cycle through the night.

We are going to build two 12V LiFePO4 420Ah cells that are going to be charged with a combination of 4 250W panels and a 1500W wind turbine. We will be adding to the system in the future with more panels and cells as we see fit to what to add to the system. Our goal is to get the property completely fossil fuel independent. If it wasn't for a well pump turning on we would need less than 1500W to run peak times during the summer days and less than 600W at night. This is the power needed to operate our 3-30foot travel trailers.

So now you know what was what.

 

[Delmar]

Thanks the additional info, I found it entertaining. Sorry made some erroneous assumptions from your original posting that you required more power than stated.

I am a generator guy but hardly an expert. I worked at Waukesha Engine in the late 70’s/early 80’s at their Power Systems division designing large gensets. However most of my engine knowledge was absorbed from my late father who was a lifer in the Waukesha service department, retiring as National Service Manager.

After Waukesha I worked at Generac designing their portable generators and large transfer switches. Guess I like having a generator around when all else fails. I am currently installing a 14kw at my moms house that will also power my house via charging my golf cart. I would have downsized the 14kw too, however need the big surge to start a 3 ton AC. Thankfully natural gas is more forgiving than diesel.

 

[JG51Ogg]

Thanks the additional info, I found it entertaining. Sorry made some erroneous assumptions from your original posting that you required more power than stated.

I am a generator guy but hardly an expert. I worked at Waukesha Engine in the late 70’s/early 80’s at their Power Systems division designing large gensets. However most of my engine knowledge was absorbed from my late father who was a lifer in the Waukesha service department, retiring as National Service Manager.

After Waukesha I worked at Generac designing their portable generators and large transfer switches. Guess I like having a generator around when all else fails. I am currently installing a 14kw at my moms house that will also power my house via charging my golf cart. I would have downsized the 14kw too, however need the big surge to start a 3 ton AC. Thankfully natural gas is more forgiving than diesel.

It has been a comedy of problems over the last 17 years and we don't want to have to work on things any more. Our kids don't understand how to keep the squirrels running in the cages so if we can get it down over the next five years to be self sufficient year round without the need for fossil fuels then we have done our jobs and like our money they can enjoy this also.

 

[Hedges]

Our kids don't understand how to keep the squirrels running in the cages so if we can get it down over the next five years to be self sufficient year round without the need for fossil fuels then we have done our jobs and like our money they can enjoy this also.

A large enough PV system, loads controlled based on SoC and surplus solar production.
If you can, redundancy and a simple switch to bypass something that has failed.

Since mine is grid-backup, I have an interlocked breaker transfer switch to let my wife enable grid-direct if power goes out due to inverter failure. For you, possibly two parallel systems and each set of loads with a transfer switch to pick either system.

"4A no use draw" x 12V = 50W, x 24 hours = 1200 Wh/day.

"2-250W panels" for 500W (STC), 6 hours effective sun in summer, 2 hours winter. 3000 Wh/day and 1000 Wh/day.
You need lots more panels.

 

[JG51Ogg]

A large enough PV system, loads controlled based on SoC and surplus solar production.
If you can, redundancy and a simple switch to bypass something that has failed.

Since mine is grid-backup, I have an interlocked breaker transfer switch to let my wife enable grid-direct if power goes out due to inverter failure. For you, possibly two parallel systems and each set of loads with a transfer switch to pick either system.

"4A no use draw" x 12V = 50W, x 24 hours = 1200 Wh/day.

"2-250W panels" for 500W (STC), 6 hours effective sun in summer, 2 hours winter. 3000 Wh/day and 1000 Wh/day.
You need lots more panels.

Without getting too far into the system. If what we are building (solar) fails there is a backup gasoline 4500W Generac generator. They simply remove the 30A 110 plug from the invertor and plug it into the Generac 30A 110 plug. They only need to switch the primary power breaker off when transferring the plug then turn it back on once it is in place. We are doing it with solar so we don't have to listen to a running Generator at any time.